You gonna find in that repository 3 files. You have to converte the 3 files from TS to Java.
First of all you should find a way to create Arrays in Java (because Java arrays are not flexibles as in JS/TS and should not be used in our current case) You will also face the import issue, you could use an IDE which will import class for you or you could search on the internet how to properly import in Java.
Good luck !